1. Field Of Invention
The present invention relates to a seat apparatus, and in particular, to a seat apparatus wherein a seat-back is brought into reclining movement relative to a seat-cushion.
2. Description of Related Art
A conventional seat apparatus of the kind disclosed in, for example, Japanese Patent Laid-open Print No. Hei2-128707 published in 1990 without examination includes a lower arm for fixing a seat-cushion and an upper arm for fixing a seat-back. A shaft pivots the upper arm to the lower arm, a locking mechanism, which is disposed between the lower arm and the upper arm, has a combination of a pawl and a ratchet and a cam rotatably mounted on the shaft for moving the pawl, wherein an engagement between the pawl and the ratchet is maintained by establishing an engagement between the cam and the pawl in order to prevent a reclining movement of the seat-back relative to the seat-cushion. The reclining movement of the seat-back relative to the seat-cushion is permitted when the cam is released from the pawl. A clearance is defined between the cam and the shaft in order to ensure the engagement therebetween to compensate for manufacturing tolerances.
However, such a clearance sometimes may bring about an unexpected movement of the cam, thereby causing an incorrect or imperfect engagement between the cam and the pawl.